عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Background and objectives: Bitter apple (Citrullus colocynthis L.) is one of the most important plant in traditional medicine that grows at arid and semi-arid conditions, little information about agronomic requirement of bitter apple is avalable. Among different agricultural managements, sowing date and plant density are the main factors for achiving highest yield.This study was conducted for evaluating the effects of sowing date and plant density on yield and yield components of bitter apple.
Materials and methods: A field study was conducted as a split plot design based on a Randomized Complete Block design (RCB) with three replications at farm in Sabzevar, Iran in 2013. The main plots consisted of sowing date (4 April, 5 May, 5 June) and the sub plots consisted of plant density (2, 4, 8 plant.m-2). At harvesting time, number of fruit per square meter, fruit dry matter, number of seed per fruit, 100 seeds weight, biological yield, fruit and seed yield, harvest index were measured as quantitative variables and colocynthin and cucurbitacin content were measured as qualitative variables.
Results: The result of analysis of variance showed that plant density and sowing date had significant effect on all studied traits but interactions between most of the studied traits were not significant. Delaying in sowing date significantly decreased number of fruit per square meter, biological yield, fruit and seed yield, harvest index, colocynthin and cucurbitacin content whereas seed weight and number of seed per fruit did not affect by sowing date.There was no significant difference between sowing date on June 4 and May 5 for number and dry matter of fruit, seed yield, harvest index, colocynthin and cucurbitacin content. Sowing date of June 5 had the highest fruit dry matter that had no significant difference with April 4. Increasing plant density was increased number fruit, biological yield, fruit and seed yield, colocynthin and cucurbitacin content. Plant density did not significantly effect on fruit dry matter, the number of seed per fruit, 100 seed weight and harvest index. There were no significant difference between 4 and 8 plant.m-2 for fruit number per square meter, biological yield, fruit yield and seed yield, colocynthin and cucurbitacin content.
Conclusion: Overall, the result of this experiment showed that the highest seed yield and fruit yield were obtained on April 4 sowing date and 4 plant.m-2. In terms of quality of active components, the best sowing date and plant density were on May 5 and 8 plant.m-2 for cucurbitacin and 2 plant.m-2 for colocynthin.