Herbicide Challenges

My greatest challenge with center pivot rice research in South Africa has been weed control. Since rice is not a normal crop in the country, none of the major rice herbicides such as propanil and quinclorac (Facet) are available here. We are utilizing multiple-crop herbicides already available here (ex. clomazone, pendathalin, 2,4-D) while working with chemical reps to get better herbicides for next year through legal channels. The chemicals that we are using now are effective for controlling weeds at higher rates but often cause significant crop injury. Shortly after I arrive here in early January, the rice was in mid-tiller growth stage with a medium infestation of Wandering Jew and wild watermelons. Later that week, 2,4-D was applied with a sprayer. Unfortunately, less than an hour after the applicator left the field a rain shower occurred. The rice tolerated the 2,4-D well but the many of the weeds recovered because the chemical was washed off. Over the next two weeks, it rained some almost every day. When the weather finally cleared to spray the rice again, the rice stem internodes were beginning to elongate indicating the beginning of reproduction growth stage. In the second application, the 2,4-D killed the weeds but also caused the rice leaves and stems to turn yellow. Hopefully, the plants will recover soon enough to produce normal panicles.

Last week, I was invited by the Limpopo Agriculture Department to make three on-farm visits. We went to the Greater Sekhukhume District, which is one of the poorest and driest areas of South Africa. Two of the three groups that I visited were working with partners in crop share rental arrangements similar to many farmers that I work with in the Bootheel of Missouri. In South Africa, often the land is owned by a tribe that divides the income between many families. One of the goals of schemes is to transfer modern farming skills from the partner to the landowners. If successful, over time, they would be able to profitably be able to manage their land on their own. Maize (corn) was the major crop being produced on the land with over-head sprinkler irrigation. The last group that we visited grow vegetables such as tomatoes.

Their challenges were getting their produce to market, controlling a particular unknown weed, and a need for an additional tractor.