油菜产量因素预测方法研究

以油菜单株第一分枝数、单株籽粒质量、单株荚果数、千粒质量、籽粒与茎秆比、产量等为预测对象,利用观测品种同为秦油2号的淮安站1995—2004年油菜农业气象观测资料及对应的气象观测资料,充分考虑油菜各生育阶段的生理特性及其对气象条件的不同要求,梳理确定育苗期≥0℃有效积温等35个气象因子,分别采用多元线性回归及BP神经网络等2种方法构建油菜产量因素的预测模型,并利用观测品种也为秦油2号的镇江站及射阳站1996—2000年、金坛站1997—2000年数据资料验证所构建模型的预测效果。对比分析2种模型的预测效果发现,BP神经网络模型在预测精度和稳定性上均优于线性回归模型,能对具有交互作用下的众多气象因子和产量因子进行非线性映射,可以更好地反映出油菜产量因素与相关气象因子间的函数关系。

Correlation Analysis Between Yield Components and Yield Per Plant of Double-low Hybrid Rapeseed

[Objective] The experiment aimed to study the relation between yield components and yield per plant of double-low hybrid rapeseed and provide reference for breaking yield limitation of rapeseed and culturing new double-low hybrid rapeseed variety. [Method]The yield components and yield per plant of two cross combination of double-low hybrid rapeseed (B02, D04) and Shuza 6 were correlatively analyzed and compared, besides, the path analysis was also carried on to them. [Result] Among B02, D04 and Shuza No.6, effective pod number per plant and seeds per silique, seeds per pod and 1 000-grain weight were all negative correlation. In high yield hybrid, pod number per plant, seeds per pod had more impaction on yield per plant than 1 000-grain weight and the difference was at 0.01 significant level. In the control variety Shuza No.6, the impactions of pod number per plant and seeds per pod on yield per plant were bigger than that of 1 000-grain weight on yield per plant, however, the difference was not significant. [Conclusion] The improvement of effective pod number per plant was an important aim of breeding work of double low rapeseed breeding in Sichuan ecological region.

Effects of Main Cultivation Factors on Rapeseed Oil Yield

[Objective] This study aimed to analyze the influence of six cultivation fac- tors： sowing date, plant density, nitrogen fertilizer amount, phosphate fertilizer amount, potash fertilizer amount and boron fertilizer amount on seed oil yield of Brassica napus. [Method] Statistical analysis was carried out based on the data from previous studies and our work. [Result] Oil yield shared a negative correlation with sowing date, a parabolic relationship with plant density mostly, parabolic rela- tionships with amount of applied nitrogen fertilizer and amount of applied boron fer- tilizer, straight-line relationships with amount of applied phosphate fertilizer and amount of applied potash fertilizer. The average amount of applied nitrogen fertilizer required to obtain the highest oil yield was 185.18 kg/hm2 for high-oil rape varieties （with oil content above 44.00%）, and under this condition, the average oil yield of low-oil rape varieties （with oil content below 42.00%） was 1 247.84 kg/hm2, while that of high-oil rape varieties was 1 442.60 kg/hm2, which was 15.61% more than the former. The average amount of applied nitrogen fertilizer required to obtain the highest oil yield for lower-oil rape varieties was 286.28 kg/hm2, and under this con- dition, the average oil yield of the low-oil rape varieties was 1 350.57 kg/hm2, while that of the high-oil varieties was 6.81% higher than it. There was a significant neg- ative correlation between rapeseed oil yield and the amount of applied nitrogen fer- tilizer to obtain the highest oil yield （0.980 0）. The optimum amount of applied ni- trogen, phosphate, potash and boron fertilizer were 187.5-195, 187.5-195, 105-120, 135-150 and 15-22.5 kg/hm2 for high-oil B. napus varieties. [Conclusion] This study determined the influence of sowing date, plant density and amount of applied nitro- gen fertilizer on oil yield of B. napus, and proposed an optimum cultivation pattern for high-oil varieties.

Responses of Seed Yield and Economic Benefit of Winter Oilseed Rape(Brassica napus L.) to Different NPK Ratio and Dose

Field experiments were conducted during 2008-2010 to investigate the ef- fects of NPK fertilization on seed yield and economic benefit of a new hybrid cultivar of winter oilseed rape （Brassica napus L.） - Xiangzayou763, and to determine the optimum NPK ratio and dose in Hunan, China. The results showed that NPK ratio （1：0.50：0.50） with 180 kg/hm2 N, 90 kg/hm2 P2O5 and 90 kg/hm2 K20 was the optimum combination for the highest seed yield （2 231.13 kg/hm2） and economic benefit （9 816.97 Yuan/hm2）, of which 1 641.23 Yuan/hm2 being set for fertilizer in- vestment （VCR=4.11）. Besides, the effects of N, P and K fertilizers on seed yield and oil production of winter oilseed rape were not identical. N had the greatest ef- fect on plant growth of winter oilseed rape, followed by P and K. Total leaf number, green leaf number, leaf length and width, rhizome diameter, branch number, dry weight per plant and other agronomic characters in high N treatments were higher than those in low N treatments. By correlation and path analysis of yield components, the contribution rate to seed yield was found： effective silique number per plant〉seed number per silique〉l 000-seed weight.