By Shah Khalid Shah Jee
In general, the months of May and June are considered to be the warmest months of summer in the Malakand Division (Pakistan), with temperatures rising above 38 degrees Celsius. This year, unusually heavy rains have swept across the country in May and June, events that meteorologists have described as a clear indication of climate change. The Malakand Division received more unseasonal rains in April and May than other parts of the country and it currently rains here on an almost daily basis. These rains have brought about many fundamental changes in orchards, crops and soil properties over the seasons. For many years before, the weather remained pleasant even in the summer until May and mid-June and people did not feel the heat as strongly as they do now.
Dr. Roshan Ali, a senior soil fertility scientist and meteorologist at the Swat Agricultural Research Institute, who has been closely monitoring the weather and climate change in the Malakand Division, told us about climate change over many years in an exclusive interview. Dr. Ali has been observing momentary weather changes in the Division and is keeping records. According to his research, the Upper Malakand Division, which includes Upper Swat, Upper Dir and Upper Bajaur, has received more untimely rains than the plains of Malakand Division. Also the timing of the rains has changed, and untimely rainfall has increased. This change has been observed for the last three or four years, but this year has seen a dramatic increase. 559 mm of rain has fallen from January 2020 to June 15, 2020. If you look at the amount of rain over the last ten years, total rainfall has not only decreased from 1500-1200mm per year to 800-600mm per year, the rains are now also more common before April, May and June 15, during which time most fruit-bearing plants yield their flowers, affecting their yields. For example, due to these untimely heavy rains, the following four major changes have taken place.
1: Changes in Chill Hours
Chill Hours are hours that range from 0 to 7 degrees Celsius that are recorded from October to March. Since the previous six months used to be continously rainy, this amount of hours used to be higher, but now the weather is mostly dry from October to November, and the amount of chill hours has started to decrease. This has resulted in higher yields for some fruits, but production of others has decreased. The required chill hours vary for different fruits such as 850 to 980 hours for peaches, 850 to 1500 hours for apples, 150 to 700 hours for walnuts, and 100 to 200 hours for pomegranates. It takes 100 to 1000 hours for grapes and 400 to 500 hours for plums to chill. If the flowers grow immediately after the completion of these chill hours, followed by more rain immediately after the flowering, then the yield will be affected. Similarly, if the required number of chill hours for a certain plant is not met, its yield will be affected. This year, the Agricultural Research Institute has recorded 980 hours, which is enough for some plants and not enough for other plants. Many varieties of apples for example, did not receive enough chill hours, so apple orchards are with sufficient yields are limited to the Upper Swat Kalam region. Similarly, the yield of Earligrand (a peach variety) has decreased, while the production of Spring Crust (another peach variety) has not been much affected because the Earligrand variety required less chill hours. As a result, the flowers that grew were damaged due to heavy rains, in its turn affecting production.
2: Affected pollination
The second change is that there is more rain at flowering time. This year, this affected fruit-bearing, cross-pollinated plants because bees do not visit the flowers due to the rain. The pollination process was affected for crops such as red beet plum, some varieties of apples and other fruit-bearing plants which are cross-pollinated, and they did not bear fruit as they used to.
3: Decrease in soil fertility
The third major change that was more noticeable in the upper areas of the Malakand Division due to these untimely and erratic rains was the lack of important components in the soil. Such components get swept away by the rains and plants can no longer get enough nutrients from the soil. Farmers have started to complain about their crops not producing well. Low levels of calcium, iron, nitrate, boron and potash have been observed which has weakened the soil and adversely affected its productivity. Iron and magnesium deficiency cause photosynthesis in crops to fail and crops cannot be fully nourished, causing their leaves to fall off. Strong winds, also a consequence of climate change according to Dr. Ali, have also affected the crops this year.
4: Increase of diseases and pests
As a result of untimely heavy rains, the wheat crop was affected by summit and rust diseases, which decreased production this year. Locust attacks as a result of climate change have also caused further damage. When this occurs, Dr. Ali would advise famers not to apply all the fertilizers in their fields at cultivation time but to apply nitrogen fertilizers in installments and use more organic fertilizers as well as use whatever is needed in the field as per the advice of agronomists. Farmers are advised against experimenting with fertilizers on their own because sometimes the land requires one thing and the landlord provides something else, doing more harm than good. Farmers should only cultivate certified seeds and consult agronomists before applying sprays and fertilizers on crops to avoid financial loss.