Yield Of Sunflower Crop Research Articles

Effect of tannery effluents on seed germination and growth of two sunflower cultivars

The wastewater of a tannery in Multan, Pakistan, was alkaline with high biochemical oxygen demand (BOD) and chemical oxygen demand (COD) values along with much higher concentrations of total settle able salts and suspended solids, sodium adsorption ratio and high amount of sodium having the water quality class C 3 S 1 . Effluent was examined for its chemical constituents and the effect of its various dilutions was examined in greenhouse on two newly recommended sunflower cultivars (FH-330 and FH- 245) during their whole growth period. Percentage of germination, chlorophyll, carbohydrates and protein contents of both the sunflower cultivars showed significant (p = 0.05) decreasing trend with increasing effluent concentrations. Vegetative growth parameters like plant height and number of leaves per plant were significantly (p = 0.05) reduced with the increasing levels of effluents. Rate of leaf senescence of both cultivars was higher under higher effluent concentrations. Yield of sunflower crop in both cultivars was significantly (p = 0.05) reduced due to effluent concentrations. Seeds per capitulum were decreased to 49%, seeds weight per plant to 61 - 66% and 100-seed weight to 49 - 59%. The appearance of pale yellowish color of the affected plants was due to reduction in photosynthetic material under higher effluent concentration. Full strength effluent concentration caused the reduction in biomass accumulation and reproductive growth of sunflower cultivars. The results revealed that cultivar FH-330 was relatively resistant to varying effluent concentrations as compared to the cultivar FH- 245. However, the tannery effluents due to the presence of chemicals are not suitable for inclusion in irrigation system. Key words : Tannery effluents, sunflower, seed germination, growth, adverse effect, reduced yield.

Sunflower disease and insect pests in Pakistan: A review

Sun flower (Helianthus annuus L.) is one of the important oil seed crops and potentially fit in agricultural system and oil production sector of Pakistan. Various diseases, insects and nematodes attack damage the sunflower crop, results a wide range of loss in production and yield. Sunflower is susceptible to diseases of various kinds. The most serious diseases of sunflower are caused by fungi. The major diseases include rust, downy mildew, Verticillium wilt, Sclerotinia stalk and head rot, charcoal rot, blight and leaf spot. The severity of these diseases affects on crop yield. An account of important sunflower pests is discussed for brief understanding low yield of sunflower crop in Pakistan.