Coconut diseases

Coconut diseases

The number one supplier of coconut is the Philippines for about seventy percent (70%) aggregate the worlds export. The total area planted to coconut is about 3.1 million hectares. However, annual nut production has decreased. This decline in coconut production and productivity is attributed to several constraints, such as unfavourable environmental factors, improper cultural practices, inferior planting materials and unfavourable socioeconomic conditions. Disease of coconut the cadang-cadang its symptoms are minute yellow spots appear on the leaflets which are water-soaked and olivaceous, turning the lower two-thirds of the crown yellow to bronze. The spots enlarge and coalesce, forming streaks parallel to the leaf veins. Young leaves in the center of the crown become shorter and more upright. The lower fronds fall off faster than the formation of new fronds thus, reducing the crown to a tuff of new upright leaves. The ways how to control it is to cut and burn infected parts. Then replace them with seedlings grown from nuts produced by survivor palms in infected areas or from early-bearing dwarfs and hybrids. The Socorro Wilt its symptoms include premature senescence of the foliage starting from the oldest to the youngest fronds.  Premature nutfall to eventual cessation of reproductive growth, root rot, as well as the seemingly partially-dehydrated appearance of the trunk portion just below the crown.  Socorro wilt kills affected palms within three to seven months from the appearance of initial symptoms. And the ways how to control it are cut and burn diseased palms immediately to reduce sources of infection. Search for disease- resistant or tolerant coconut cultivars/hybrids is also being done. Next is the Stem Bleeding its symptoms infected palm may be detected by the exudation or oozing out of a reddish-brown fluid from cracks in any portion of the trunk. Upon drying, the color of the oozed substance changes from dark brown to almost black. Tissues adjacent or underneath the bleeding portion of the trunk become yellowish and rotten. To control stem bleeding is to chisel out the infected tissues including about 5 cm of the healthy portion. The chisel should be flamed first before each thrust to prevent the instrument from carrying an infectious load of inoculum. The cut should be as smooth as possible to avoid accumulation of the plant sap. Dress the exposed areas with hot tar or copper sulphate-lime paste. Spray copper fungicide at 3 tbsp/4.5 liters water. Next disease is Dry Bud Rot symptoms it is characterized by the dry rotting of the growing point without emitting foul odor. The cause of the disease is still unknown. The way to control it is to isolate and burn infected seedlings immediately. The Dry Frond Rot its symptoms is infection may start at any mid-portion of the rachis of a diseased frond.  At first, spots are noticeable as small pin-pricked lesions with diminished yellow haloes after which they advance and become brown. Lesions appear to have no distinct concentric brown zones developing into more or less oblong shapes with varying sizes. Under favourable conditions, the spots coalesce and form dead areas or blight of the frond in which case the rachis eventually dries up causing premature senescence of affected fronds. To control the Dry Frond is to phytosanitation and cultural management should be practiced on reported diseased areas. Copper fungicides, dithiocarbamate, and chlorothalonil may be effective. Leaf Spots its symptoms are the leaf spot caused by P. Palmarum  are small, yellowish-brown, circular lesions which later turn brown with gray centers. As the spots enlarge, adjacent ones coalesce, forming larger lesions. The tips and margins of infected leaflets dry up,  giving the leaf a blighted appearance. On the other hand, Helminthosporium sp. causes small, brown, sunken, necrotic lesions which enlarge and coalesce, resulting in the drying up of severely infected leaflets. The fungus is transferred to healthy plants by wind, water splashes, insects, or by mechanical means.