ITEMS FROM INDIA

INDIAN AGRICULTURE RESEARCH INSTITUTE

Division of Genetics, New Delhi 1100 012, India.

Vidisha (DL 788-2) - a high-quality rust-resistant wheat with potential for high and stable yields.

R.N. Sawhney.

Vidisha (DL 788-2) was derived from a locally adapted cross involving K 7537, HD 2160 mutant, HD 2278, and DL 896-2. The last parent is a white-seeded Kalyansona backcross derivative with Lr24/Sr24 resistance from Ag. elongatum. The cultivar was released officially in March, 1997, for cultivation in the central zone comprising Madhya Pradesh, Gujarat, and parts of Rajasthan. Vidisha is recommended as a replacement for Lok 1, a popular wheat released in 1981. Lok 1 has become highly susceptible to leaf and stem rusts, the most prevalent diseases in the region. Vidisha has an excellent plant type with ideal plant height (75­90 cm), profuse tillering, and resistance to lodging.

Yield performance in the Central zone. During 3 years of testing in late-sown irrigated trials, the average yield of DL 788-2 was 3.93 T/ha compared to the checks Lok 1 and GW 173, which yielded 3.76 T/ha and 3.88 T/ha, respectively. Further evidence of the superority of DL 788-2 over the check cultivars is its presence in the nonsignificant group in 20 out of 36 trials, compared to Lok 1 (16/36) and GW 173 (14/28). A maximum yield of 5.6 T/ha was recorded by DL 788-2 at Gwalior in 1994­95. Agronomic data in coördinated trials revealed that the percentage decline in yield was higher in Lok 1 (28.90 %) compared to DL788-2 (22.8 %) when late-sown.

Yield performance in the Northern Plains zone. Vidisha was evaluated along with the checks HW234 and HP1633 (Sonali) in an irrigated, late-sown series of Advanced Varietal Coordinated Trials between 1992-93 and l995-96. Both DL 788-2 and HW234 yielded 3.58 T/ha. Sonali (HD 1633), the latest release, produced 3.08 T/ha.

Yield performance in the North West Plains zone. Vidisha also suscessfully completed 3 years of testing (1990-91 to 1992-93) in the North West Plains Zone in a timely sown, irrigated set of the All India Coordinated Trials. Averaged over 3 years, DL 788-2 yielded 4.68 T/ha, whereas HD 2329, the most popular wheat in the region yielded 4.57 T/ha. A maximum yield of 5.9 T/ha was reported from Tabiji (U.P.), compared to the popular check HD 2329, which yielded 5.6 T/ha. Furthermore, in tests to identify new cultivars suited to different planting times by the Agronomy Department at IARI, DL 788-2 yielded the highest (5.25 T/ha) followed by HD 2329 (4.8 T/ha) and PBW 327 (4.26 T/ha) in timely sown, irrigated conditions (IARI News, 10(2), 1994).

The yield performance detailed above demonstrates that DL 788-2 has a high yield potential coupled with a plasticity that allows it to adjust to a wide range of sowing times from normal (in the NWPZ) to late (Central Zone­Eastern Zone), depending upon the growing period. The superior performance of DL 788-2 across diverse agronomic conditions and management practices suggests that the cultivar has potential to provide stable production.

Resistance to disease. Vidisha has inherited the alien genes for leaf and stem rust resistance (Lr24/Sr24) from the white-seeded stock TR 380 (27*4 / 3 Ag # 3) from Ag. elongatum. Tests in the Pathological Screening Nursery (PPSN) recorded a leaf rust infection score of 10 MR to 10MS, with an average coefficient of infecton (ACI) ranging from 2.0 to 8.0 for DL 788-2, compared to the check Lok 1, with 80S to 100S and an ACI from 42.8 to 68.3. Similarly, the ACI for stem rust of DL 788-2 was between 3.0 and 9.5, compared to the checks (29.0 to 58.4) was quite low. Seedling resistance to stem rust pathotypes 34-1 and 40-1, pathogenic on lines with Sr24, suggests that DL 788-2 has additional resistance genes. Sr2, a partially effective adult plant resistance gene associated with durability, and Sr5 possibly explain the high degree of resistance even to races pathogenic on Sr24. Vidisha also has complete seedling resistance to leaf rust, making it dificult to identify other leaf rust-resistance genes that may be present. The cultivar provides as yet unexploited diversity for resistance to rusts.

The high degree of stem and leaf rust resistance in DL 788-2, in contrast to the high levels of susceptibility in Lok 1 to both the rusts, warrants quick replacement of this most popular and widely cultivated wheat in the region. Likewise, HD 2329, the most popular and extensively grown wheat in the northwest parts of the country, has become susceptible to rust diseases and should be replaced with DL 788-2.

Quality characteristics. The quality traits of DL 788-2 and Lok 1, a wheat known for high quality in Central India, are described in Table 1.

DL 788-2 has demonstrated yield superiority over the best checks under diverse production conditions and in different agroclimatic zones. The cultivar has wide adaptibility, high levels of rust resistance, and superior grain quality. Vidisha is expected to be received well by both farmers and consumers, even as a substitute for Lok 1, which at present is known as a high quality wheat in the country.

Summary. Vidisha (DL 788-2) was devloped from a cross involving Kalyansona backcross derivatives with Lr24/Sr24 from Ag. elongatum as a parent. The cultivar was officially released in 1997 for the late-sown cultivation in the Central zone. DL 788-2 has excellent plant type with ideal plant height, profuse tillering, and resistance to lodging. Multiple site trials under diverse agroclimatic regions and management practices demonstrated that DL 788 2 has a high yield potential coupled with an adaptibility to a wide range of sowing times and production conditions reflecting a stable productivity. A high degree of resistance to stem and leaf rusts provides a new source of resistance. Comparitive performance for quality parameters has estblished DL 788-2 as a better alternative to DL 788-2 and Lok 1, popular and high quality wheats.

MARATHWADA AGRICULTURAL UNIVERSITY

Wheat and Maize Research Unit, Parbhani 431 402 Maharashtra, India.

Influence of neem extract-coated urea on the quality of wheat grain.

S.T. Shirale and K.A. Nayeem.

This experiment was conducted at the Cotton Research Scheme, Marathwada Agricultural University, Parbhani. The experimental area was characterized by black cotton soil dominated by montmorillonite clay with a pH of 7.9. Clacareous in nature, the soil was deficient in phosphorus (22.4 kg/ha), average in nitrogen (2.09 kg/ha), and high in potassium (312.8 kg/ha). Nine treatments with four levels of nitrogen (60, 80, 100, and 120 kg/ha) were applied as prilled (pelleted) and neem seed extract coated urea. The control had no urea application. A uniform dose of 60 kg P2O5 and 60 kg K2O per ha was applied to all treatments.

The maximum carbohydrate content of 82 % was recorded in the T9 treatment (120 kg/ha), although the neem seed extract-coated urea was significantly higher than all the treatments including the control (T1 treatment, no nitrogen) (Table 1). The T9 treatment also exhibited the highest protein content at 11.85 % and was significantly superior to all treatments except T8, the 100 kg neem seed extract-coated urea (see Table 1).

Application of neem seed extract-coated urea increased seed size and weight. We found that the T9 treatment produced a 1,000 kernel weight of 41.50 g and was superior to all treatments.

References.

Roy B. 1988. Coated and modified urea material for increasing nitrogen use efficiency of low land rice in heavy clay soil. Fert Res 15:105-109.

Vyas BN, Godrej NB, and Mistry KB. 1991. Development and evaluation of neem extract as a coating for urea fertilizers. Fert News 2:19-24.

PUNJAB AGRICULTURAL UNIVERSITY

Regional Research Station, Ropar-140001, Punjab, India.

Evaluation of rye and wild wheat accessions for resistance to flood injury.

S.S. Bains, H.S. Dhaliwal, and Sukhchain.

Accessions of S. cereale (6), Ae. speltoides (37), Ae. squarrosa (60), Ae. triuncialis (2), Ae. ovata (15), Ae. bicornis (2), Ae. lorentii (11), Ae. triaristata (2), Ae. cylindrica (23), Ae. kotschyi (1), Ae. ventricosa (2), Ae. longissima (6), Ae. columnaris (2), Ae. umbellulata (4), T. araraticum (55), T. urartu (36), T. dicoccoides (98), and T. boeoticum (114) were sown in 13 different beds. Each bed was flooded with 15 cm of water for 3, 8, and 20 days starting at 50, 80, and 120 days after sowing, respectively.

Flooding for 3 and 6 days starting at 50 and 80 days after sowing, respectively, produced no visible adverse effects on the test accessions. However, flooding for 20 continuous days starting at 120 days after sowing had drastic effects on several accessions. Only seven accessions (3582, 3593, 3594, 3597, 3599, 3600, and 3603) of Ae. speltoides survived the flood injury. No accession from other species survived. Certain accessions of Ae. speltoides (3713 and 13749); Ae. squarrosa (3766, 9807, and 3469); Ae. triuncialis (3561, 3618, 3624, 3625, 3627, 3630, 3649, 3652, 3679, 3681,and 3795); Ae. cylindrica (3644 and 3698); Ae. lorentii (3543, 3550, 3551, 3677, 3719, 3720, and 3801); Ae. ovata (3640, 3641, 3654, 3687, 3673, and 3798); Ae. bicornis (3520); Ae. umbellulata (13779); T. araraticum (4731 and 4763); T. urartu (5305, 5306, 5322, 5336, 5345, 5347, and 5351); T. dicoccoides (4848); and T. boeoticum (4795, 4866, 4881,4883, 4879, 4922, 4932, 4935, 4954, 4992, 5054, 5078, 5149, and 5166), and S. cereale (3732) were submerged completely because of their short height. None survived, and their mortality could have been due to submergence rather than injury to the root system.

The effect of incubation of water-soaked seed under gunny bag cover on the incidence of loose smut in wheat.

S.S. Bains and Hardip Singh.

Water-soaked wheat seed is piled under damp gunny bags for sprouting before sowing at late planting dates. We investigated the effect of this practice and other treatments on loose smut transission through seed. The data exhibiting the relative efficacy of different treatments are presented.

Loose smut-infected seeds of the wheat cultivar JL 711 were obtained through repeated dustings of teliospores on spikes at anthesis for several days during March. The inoculated spikes were harvested manually and threshed, and the cleaned seeds stored in cloth bags in the laboratory. The seeds were sown in November of each year (1994-95) at Punjab Agricultural University, Regional Research Station, Gurdaspur. In each case, the inoculated seeds were divided into 13 lots and individual lots were given the desired treatment, i.e., soaked in water for different periods of time (8, 12, 24, and 48 hr); covered with damp gunny bags for different periods (8, 12, and 24 hr) following soaking in water for 8 hr; or treated with Vitavax (0.3) following soaking in water for 8, 12, 24, and 48 hr. Dry seeds, similarly treated with Vitavax, were used for comparison. The seeds from each treatment were sown in a 2-m, 2-row plot, and randomly replicated four times. Thereafter, the crop received fertilizer as recommended for wheat in grown in Punjab. The data were recorded by direct counting of smutted and healthy plants in March of both years. The data computed as percent of smutted plants are presented in Table 1.

The incidence of loose smut was reduced from 9.2 % in the control to 6.6 % in seed soaked in water for 8 hr. An increase in the water-soaking period (up to 48 hr) further reduced the incidence of loose smut. However, this decrease was not statistically significant. The seed soaked in water for 8 hr and subsequently incubated under gunny bag cover for 8 hr had a significantly low incidence of loose smut compared with the control or those seeds given a water-soaked treatment. Loose smut incidence further decreased as the incubation under gunny bags was increased to 24 hr (Table 1). Seed treatment with Vitavax resulted in complete control of loose smut, whether or not the seed received a presoaking period (Table 1).

All treatments decreased the incidence of loose smut by various levels in this study. Incubating water soaked seed under gunny bags, a practice used to sprout seeds before planting, significantly reduced loose smut incidence. Thus, in addition to the other benefits of the treatment, control of loose smut also was achieved.