Seed Health Management for Better Productivity - Govind Ballabh ...

(Seed Health Management for Better Productivity)high occurrence of the floral infection (staghead phase) of white rust and downy mildew duringflowering period has been found to be associated with reduced period, i.e. 2-6 hours, of brightsunshine/day concomitant with the mean maximum temperature of 21-25 0 C, the meanminimum temperature of 6-10 0 C and higher total rainfall up to 166 mm. Bright sunshine hours/day has a significant negative correlation whereas total rainfall has a significant positivecorrelation with staghead development.‣ All the three important foliar diseases of rapeseed-mustard could be effectively controlled byfollowing integrated package of balanced N 100 P 40 K 40 application, early October sowing andtreating the seed with Apron 35 SD @ 6g kg -1 seed followed by spray of mixture of metalaxyl +mancozeb (i.e Ridomil MZ 72 WP @ 0.25%) at flowering stage and by spray of mancozeb oriprodione @ 0.2% at pod formation stage. In situations where Sclerotinia stem rot and / orpowdery mildew appeared to be important in a particular crop season, a spray of mixture ofcarbendazim (0.05%) + mancozeb (0.2%) was found to give excellent cost effective control ofthe diseases with significant increase in seed yield of the crop.‣ Among the botanicals, leaf extracts of Eucalyptus globosus (5%) and Azadirchta indica (5%)have been proved to exhibit greater antifungal activity against A. brassicae and Albugocandida and showed significant reduction in the severity of Alternaria blight and white rustdiseases which was rated to be at par with mancozeb fungicide spray.‣ Some abiotic chemical nutrient salts such as calcium sulphate (1%), zinc sulphate(0.1%) andborax (0.5%) and biocontrol agents such as Trichoderma harzianum and non-aggressive Dpathotype of A.brassicae have been shown to induce systemic host resistance in mustardagainst aggressive “A” pathotype of A. brassicae and virulent race(s) of A. candida.‣ The staghead phase in B. juncea has been investigated to be due to A. candida and not due P.parasitica. Tissues at the staghead phase become more susceptible to P. parasitica thannormal tissues of the same plant.‣ B. juncea genotypes (EC 399296, EC 399299, EC 399301, EC 399313, PAB-9535, DivyaSelection-2 and PAB 9511), B. napus genotypes (EC 338997, BNS-4) and B. carinata (PBC-9221) have been shown to possess resistance to white rust coupled with high degree oftolerance to Alternaria blight. Reduced sporulation is identified to be the major component forslow blighting.‣ B. juncea (RESJ 836), B. rapa (RESR 219) and B. napus (EC 339000) have been selected forresistance to downy mildew and for high yield performance. Total 52 genotypes of mustardrepresenting at least 12 differential resistance sources, 23 lines of yellow sarson representing6 differential resistance sources and 54 lines of B. napus representing 3 differential resistancesources to downy mildew have been identified.‣ A new short duration (95-100 days) short statured (85- 96 cm) plant type of mustard strain‘DIVYA’ possessing high degree of tolerance to Alternaria blight suitable for intercropping withautumn sown sugarcane and potato yielding with an average of 15-22 q ha -1 has been- 21 -