Morphological growth characteristics and main types of kidney bean plants

Green beans are actually also called kidney beans, so today I will introduce you to the basic knowledge of green beans:

Plant Introduction

Kidney beans are suitable for planting in temperate and tropical high-altitude areas. They are relatively cold-resistant and light-loving, and are cross-pollinating, sun-lit crops. Kidney beans have a well-developed root system, green, alternate, heart-shaped leaves, insect-leaf-shaped flowers, racemes, and pedicels 15-18 cm long. They bloom more and produce fewer pods. They are rich in nutrients and high in protein. They are both vegetables and grains, and can also be used as pastries and bean fillings. They are important agricultural and sideline products for export and foreign exchange earnings. Kidney beans are scientifically known as Phaseolus vulgaris, and belong to the genus Phaseolus in the Fabaceae family. Kidney beans are native to Mexico and Argentina in America, and my country began to introduce and cultivate them in the late 16th century.

Phaseolus vulgaris plant morphology

The root system is relatively well developed. The stem is left-winding and climbing, creeping, semi-climbing or dwarf. The first true leaves are simple and opposite; the later true leaves are trifoliate and nearly heart-shaped. The racemes are axillary, with butterfly-shaped flowers. The corolla is white, yellow, lavender or purple. It is self-pollinating, and a few can be cross-pollinated. Each inflorescence has several to more than 10 flowers, and generally produces 2 to 6 pods. The pods are 10 to 20 cm long, straight or slightly curved in shape, round or oblate in cross section, and the epidermis is densely covered with pubescence; the young pods are green, yellow, purple-red (or with stripes) in different shades, and yellow-white to yellow-brown when mature. As the pods develop, the vascular bundles at the dorsal and ventral sutures gradually develop, and the number of thick wall tissue layers in the mesocarp and endocarp gradually increases, and the quality of fresh food is reduced. Therefore, the young pods should be harvested in a timely manner. Each pod contains 4 to 8 seeds, which are kidney-shaped and come in red, white, yellow, black, or striped colors. The thousand-seed weight is 0.3 to 0.7 kg. The number of chromosomes is 2n=22.

Growth characteristics of kidney beans

Kidney beans like warmth and are not frost-resistant. The optimum temperature for seed germination is 20-25℃. Germination is blocked below 8℃ or above 35℃. The optimum temperature for seedling growth is 18-20℃. Seedlings will be damaged by cold at 8℃. The optimum temperature for flowering and pod formation is 20-25℃. Above 27℃ or below 15℃, incomplete flowers are likely to appear, resulting in falling flowers and pods.

Kidney beans are short-day vegetables, but most varieties are not strict about the length of the day and can be cultivated in all seasons, so they are called "green beans". They can be introduced from all over the north and south.

Kidney beans are not very demanding on soil quality, but they are suitable for growing in neutral loam with deep soil, good drainage and rich organic matter. Kidney beans require more phosphorus and potassium fertilizers, and also need nitrogen. A proper amount of nitrogen fertilizer should be supplied during the seedling and bud formation stages to ensure a high yield.

Green beans require moist conditions throughout their growing period. Due to their well-developed root system, they can tolerate a certain degree of drought. However, they are particularly sensitive to water shortage or waterlogging during flowering and podding. Too much water will cause root rot.

Main types of beans

The stem of the creeping bean grows in a left-handed spiral, with the terminal bud being a leaf bud, and lateral vines or inflorescences can form in the axils of each node; the growth period is generally 100 to 120 days; there are many inflorescences, and the flowering and pod-setting time is long, and the yield is high. The dwarf variant (P. vulgaris var. humilis) forms a terminal bud after the main stem grows 4 to 8 nodes, and the inflorescence no longer elongates; lateral branches or inflorescences occur in the axils of each node, and the terminal buds also form inflorescences after the lateral branches grow for several nodes; the growth period is generally 50 to 60 days; there are few inflorescences, flowering and pod-setting, and the yield is low. The harvest period is relatively concentrated, which is suitable for mechanized cultivation. The intermediate type between the creeping species and the dwarf species is the semi-climbing species. In addition, it can also be divided into hard-pod beans (the pods have well-developed leathery skin) and soft-pod beans (the young pods are thick and less fiber) according to the pod structure; and divided into pod species and grain species according to the use.