Rice is a major kharif cereal crop cultivated in Punjab. Over the past five decades the rice yield has increased from as low as 1800 kg/ha during 1970–4815 kg/ha during 2017, i.e., an overall increase of 167.5% or increase @ 3.5% per year. One of the major reasons for this increase has been the introduction of improved and high-yielding varieties (PR 106, PR 111, PR 116, PR 118, PR 121, PR 122, PR 126, PR 127, etc.). Other important factors are the improved crop production and protection practices coupled with mechanization of farm operations. However, weather factors have always been a major bottleneck shattering the steady plateau of high rice yield (3443 kg/ha during 1979, 3231 kg/ha during 1995, 3273 kg/ha during 1998, 4257 kg/ha during 2011 and recent low yield of 4387 kg/ha during 2018). The actual weather data of the recent two decades at Ludhiana (2000–2018) were correlated with the historical rice yield. The results revealed a combination of high temperature coupled with clear sunny (total seasonal sunshine ~ 900–1000 h) and dry (low relative humidity) days is conducive for proper growth, development and yield of rice in Punjab. The rainfall and rainy days were found to be negatively correlated with yield since heavy rainfall events and more number of rainy days create a humid weather which is conducive for insect-pest and disease incidence in rice and also reduces sunshine duration. Hence, a combination of ample sunshine hours and well-distributed rainfall during the vegetative stage of rice leads to high productivity of cultivars grown under optimized crop management techniques.

大米是主要的哈里夫旁遮普省种植的谷类作物。在过去的 50 年中，水稻产量从 1970 年的 1800 公斤/公顷增加到 2017 年的 4815 公斤/公顷，即总体增加了 167.5% 或每年增加 3.5%。这一增长的主要原因之一是引进了改良的高产品种（PR 106、PR 111、PR 116、PR 118、PR 121、PR 122、PR 126、PR 127等）。其他重要因素是作物生产和保护措施的改进以及农场作业的机械化。然而，天气因素一直是打破水稻高产（1979 年 3443 公斤/公顷，1995 年 3231 公斤/公顷，1998 年 3273 公斤/公顷，2011 年 4257 公斤/公顷和近期低产）的主要瓶颈。 2018 年为 4387 公斤/公顷）。Ludhiana（2000-2018）最近二十年的实际天气数据与历史水稻产量相关。结果表明，高温加上晴朗（总季节性日照~900-1000 小时）和干燥（低相对湿度）日的组合有利于旁遮普邦水稻的正常生长、发育和产量。发现降雨和雨天与产量呈负相关，因为暴雨事件和更多的雨天创造了潮湿的天气，有利于水稻病虫害的发生，也减少了日照时间。因此，在水稻营养阶段充足的日照时间和均匀分布的降雨相结合，可以使在优化的作物管理技术下种植的品种具有高生产力。结果表明，高温加上晴朗（总季节性日照~900-1000 小时）和干燥（低相对湿度）日的组合有利于旁遮普邦水稻的正常生长、发育和产量。发现降雨和雨天与产量呈负相关，因为暴雨事件和更多的雨天创造了潮湿的天气，有利于水稻病虫害的发生，也减少了日照时间。因此，在水稻营养阶段充足的日照时间和均匀分布的降雨相结合，可以使在优化的作物管理技术下种植的品种具有高生产力。结果表明，高温加上晴朗（总季节性日照~900-1000 小时）和干燥（低相对湿度）日的组合有利于旁遮普邦水稻的正常生长、发育和产量。发现降雨和雨天与产量呈负相关，因为暴雨事件和更多的雨天创造了潮湿的天气，有利于水稻病虫害的发生，也减少了日照时间。因此，在水稻营养阶段充足的日照时间和均匀分布的降雨相结合，可以使在优化的作物管理技术下种植的品种具有高生产力。