Sorghum and sunflower have been reported to contain several allelochemicals. Utilization of these allelochemicals is considered low-cost and natural sources for weed suppression. Field trials were undertaken at Cotton Section, Agriculture Research Institute, Tandojam Pakistan during summer 2010 and repeated during summer 2011 for validating the previous results. The experiments were laid out in three replicated randomized complete block design. The seed of cotton variety "Sindh-1" was sown through drilling in the 1 st week of May each year. The treatments consisted of: weedy check (no weeding), interculturing twice (30+60 DAS), Dual Gold 960-EC (S-metolachlor) @ 2.50 L ha -1 , sorghum water extracts @ 15 L ha -1 (twice) and 25 L ha -1 (once and twice) and sunflower water extracts @ 15 L ha -1 (twice) and 25 L ha -1 (once and twice), sorghum water extract @ 15 L ha -1 +1.25 L ha -1 Dual Gold and sunflower water extract @ 15 L ha -1 +1.25 L ha -1 Dual Gold. In interculturing the land space in between two rows of crop plants was pulverized with the help of local tool spade. The statistical analysis of data showed that interculturing, Dual Gold, and sorghum and sunflower water extracts caused significant reduction of weeds and increased seedcotton yield as compared to weedy check. The combined application of sorghum @ 15 L ha -1 + Dual Gold @ 1.25 L ha -1 resulted in weeds mortality upto 66.6%, produced seedcotton yield of 3961.4 kg ha -1 and gave net benefit of Rs. 2,20,029. Sunflower applied @ 15 L ha -1 in integration with Dual Gold @ 1.25 L ha -1 showed weeds mortality of 65.5 %, resulted in seedcotton yield of 3949.7 kg ha -1 and net monetary benefit of Rs. 2,19,821. Sole application of Dual Gold @ 2.5 L ha -1 reduced weeds by 55.9%, produced seedcotton yield of 3212.7 kg ha -1 and net resulted in net benefit of Rs. 1,77,414. It is noteworthy that interculturing twice (30+60 DAS) caused maximum (67.7%) suppression of weeds, produced maximum plant height (117.0 cm) and seedcotton yield (3977.8 kg ha -1 ) but conferred less (Rs. 2,14,151) net monetary benefits as compared to obtained in sorghum + Dual Gold and sunflower + Dual Gold. Overall results suggested that maximum net income was recorded when sorghum water extract was applied in integration with Dual Gold. The combined application of sunflower with Dual Gold ranked second in monetary benefits. Interculturing twice was found less economical due to higher costs of labour. Hence, it can be inferred from the above results that Dual Gold dose can be reduced up to 50% in combination with sorghum or sunflower water extracts for effective and environment friendly weed management and enhancing cotton yield.

Sorghum and sunflower are considered as highly allelopathic plants with inhibitory efficacy on plants of other species. In a pot study, the phytotoxic potential of sorghum and sunflower shoot and root on germination and seedling growth of cotton was evaluated through soil incorporation of powders and spray of water extracts. The experiment was conducted at | department of Agronomy, Sindh Agriculture University Tandojam during Kharif (summer) 2010 and 2011. The analysis of pooled data suggested that all the powders and water extracts of both allelopathic crops caused substantial suppression of germination and related traits of cotton seedlings as compared to control (untreated). Sorghum shoot powder (10 g kg-1 soil) caused highest allelopathic effects and reduced cotton seed germination by 12.8%, root length by 45.4%, shoot length by 51.9%, fresh weight seedling-1 by 41.7% and dry weight seedling-1 by 36.7%, followed by sunflower shoot powder (10 g kg-1 soil) in phytotoxic efficiency for inhibiting seed germination, seedling growth and weight in contrast to control (untreated). Sorghum showed superiority over sunflower in allelopathic efficiency. Powder of both crops was found more allelopathic in contrast to water extract. Among plant parts phytotoxic potential, shoot proved higher in inhibitory effect than root. However, it was concluded from the results of present study that both sorghum and sunflower possess allelopathic compounds with growth suppressing ability which could be utilized for effective weed management in cotton under field conditions as eco-friendly low-cost alternate of herbicides with wise strategy.

A field study was carried out during 2012-13 at Sindh Agriculture University, Tandojam, Pakistan, geographically latitude 25˚N and longitude 68˚E, to assess the effect of foliar applied urea on the growth and yield of sunflower. The experiment was laid out in a three-replicated Randomized Complete Block Design. Five treatments were tested against sunflower variety Hysun-33 which included: T 1 = Control (no urea), T 2 = Recommended urea soil applied (130 kg•ha −1) at sowing stage, T 3 = 1% urea at 35 days after sowing, T 4 = 1% urea at 60 days after sowing and T 5 = 1% urea at 85 days after sowing. The results revealed that growth and yield characters as well as oil yield of sunflower were significantly (P < 0.05) affected by foliar application of urea. The most effective treatment comprised of foliar application of urea (1%) after 35 days of sowing in addition to recommended soil applied urea (130 kg•ha −1) showed optimistic results with 89.61% seed germination, 179.65 cm plant height, 5.39 cm stem girth, 22.43 cm head diameter, 2063.25 grains head −1 , 68.51 g seed index/1000 seed weight, 2211.90 kg seed yield ha −1 and 1046.75 kg oil yield ha −1. The sunflower crop receiving foliar application of urea after 60 days or 85 days of sowing in addition to recommended soil applied urea ranked 2 nd and 3 rd ; and sunflower plantation given no foliar urea and grown only on recommended soil applied urea (130 kg•ha −1) ranked 4 th with 1907.96 kg•ha −1 seed yield and 841.91 kg•ha −1 oil yield. However, sunflower plantation neither given foliar application of urea nor supplied with soil applied urea (control) ranked least for all the growth and yield parameters and oil yield. Hence, it is suggested for the farmers that in addition to 130 kg•ha −1 soil applied urea, foliar application of urea (1%) after 35 days of sowing may be ensured for maximization of seed and oil yields in sunflower. The results further showed that in most cases, the crop receiving foliar application of urea after 60 and 85 days of sowing showed similarity (P > 0.05); but differences were significant (P < 0.05) when compared with foliar application after 35 days of sowing and rest of the treatments.

This study was conducted, the effects of various weed control methods to suppress the growth and development of weeds for enhancing growth and yield of maize, at the experimental area of Agronomy section, Agriculture Research Institute, Tandojam, during winter season 2011-12. The experiment was comprised of five treatments viz; T1= Weedy check, T2= Hand hoeing, T3= Mechanical, T4= Cultural and T5= Chemical weed control in randomized complete block design (RCBD) with four replications. Different weed species were found in the experimental field viz; 1 Chenopodium album L, 2 Rumex dentatus L., 3 Phalaris minor, 4 Anagallis arvensis, 5 Convolvulus arvensis, 6 Chenopodium morale L, 7 Cynodon dactylon, 8 Cyperus rotundus. Results indicated that the Leaves plant-1 , Cobs plant-1 , Plant height (cm) and Grain yield kg ha-1 of maize were significant (p<0.05) and days to tasseling and silking were non-significant (p>0.05) in all treatments except weedy check. Hand hoeing weed control method effectively reduced weeds as compared to other weed control methods. On the other hand, when weeds frequency increased significantly decreased parameters of maize. It was concluded that the hand hoeing weed control method was found suitable and effective to suppress weeds and improved grain yield of hybrid maize crop as compare to other weed control methods.

The experiment was conducted at Student Farm, Department of Agronomy, Sindh AgricultureUniversity, Tandojam during the year 2012-13, to