Growing rice plants does not detach from the threat of pests and diseases that often afflict these plants. Failure to adequately control pests and diseases can reduce the productivity of the rice plant. Therefore, farmers’ knowledge is required to be able to recognize the types of pests and diseases of rice plants, so that farmers can identify and implement appropriate, quick, and accurate control. With the control of pests and diseases, the purpose of cultivation activities is achieved. Here are some pests and diseases that can affect rice plants:
1. Shell Mas
The golden snail is one of the main pests of rice plants. The susceptible stages of rice were: nursery and rice 10 DAP. Mechanism of destruction: snails grind and eat plant tissue. Symptoms of damage: young plants are eaten, so many clumps are lost, and a rice stalk is eaten by a slug for 3-5 minutes.
Technical culture control can be carried out by:
• At the beginning of the system, namely rice aged 0-25 days, the rice fields must be drained so that the snails cannot crawl into the rice clumps to be infested. Even when attacking, the attack percentage is below the damage threshold.
• Dig a ditch around the planting area to allow the snails to congregate and destroy.
• Drains must be cleaned from aquatic plants such as kale and others to prevent them from becoming food reserves for golden snail development.
The mechanical control can be done by:
• Parent snails and eggs that are visible should all be taken and collected for destruction.
• Install a wire mesh filter at the sluice gate that opens into the paddy field to prevent the snails from getting caught and stuck in the wire.
• Provide a wooden stake as a place to place clusters of snail eggs so they can be easily picked up and discarded.
• In the crafted pit, catch bait in the form of papaya leaves or banana peels to attract and gather the snails for easy pickup and destruction.
2. Brown Planthopper
Brown planthoppers like crops that are closely spaced with high nitrogen fertilization. The economic threshold for this pest is 15 individuals per clump. Its life cycle is 21-33 days.
The control method is as follows:
• Use brown planthopper-resistant varieties.
• Apply K-fertilizer to reduce damage.
• Monitor sowing at least every 2 weeks.
• If the pest population is below the economic threshold, use botanical insecticides or entomopathogenic fungi (Metarhizium annisopliae or Beauveria bassiana).
• If the pest population is above the economic threshold, use the recommended chemical insecticide.
3. Stem drill
The main pests of rice crops, often cause severe damage and high yield losses. The stage of plants susceptible to stemborer infestation is from seedling to panicle formation. Symptoms of the damage caused result in dead shoots or often referred to as sundep in vegetative stage plants and outs (empty panicles) in generative stage plants. Symptoms of Sundeep are yellowed, dry, and dead leaves and stunted tillers. As for the symptoms of the outs, the rice panicles are brown and dry, the grain is empty, and the stalks pull out easily.
Control of this pest is carried out by:
• Plant in harmony.
• Collect groups of eggs.
• Appropriate use of pesticides.
• Spot treatment of symptomatic plants.
• Application of biological agents from egg parasitoids (Trichogramma sp.).
4. Walang Sangit
Walang sangit is a pest that commonly destroys rice grains during the ripening phase, the growth phase of rice plants susceptible to attack by walang sangit is from panicle bursting to milk ripening. The damage caused causes the rice to discolor, float, and be empty. The economic threshold of stink bugs is more than one stink bug per two clumps by the time the panicle enters the flowering phase.
The way to control it is:
• Control weeds in paddy fields and near crops.
• Fertilize the land evenly so plant growth is even.
• Use nets to catch stink bugs before they bloom.
• Bait walang sangit with rotten fish, spoiled meat, or chicken manure.
• When the attack reaches an economic threshold, spray insecticide.
• Spray early in the morning or evening when the bug is in the canopy.
• Walang Sangit pest control can also be done with golden snails.
5. Bacterial leaf blight (HDB) or crackle
HDB or crackle disease is caused by the bacterium Xanthomonas campestris PV oryzae. Crackle symptoms begin on the edges of the leaves, are grayish, and eventually, the leaves become dry. This dry part expands toward the leaf bone until the entire leaf appears dry. If the infestation occurs during flowering, the grain-filling process will become imperfect, resulting in the grain being incomplete or even empty. In such conditions, the loss of yield can reach 50-70 percent.
The realizable control principles are:
• Use of healthy seeds and seedlings.
• Use of biological agents Corynebacterium or Paenybacillus polymyxa on seeds aged 14, 28, and 42 DAP at a dose of 5 ccs per liter.
• Balanced fertilization, avoid excessive N fertilization, with sufficient P and K.
• Avoid fertilizing when the plant enters the gravid phase.
• Environmental remediation and host weeds.
• Intermittent irrigation (flooded one day, drained three days).
6. Explosive sickness
Blast can infect rice plants at all stages of growth. Typical symptoms on the leaves are diamond-shaped spots in the middle and pointed at both ends. The size of the spot is about 1-1.5-0.3-0.5 cm and develops a gray color in the center. When infection occurs in the stem and neck of the panicle (black neck), the infected panicle neck turns black and cracks, similar to the symptoms of stem borers.
The way to control it is:
• Use alternate storm-resistant varieties.
• Use nitrogen fertilizers as recommended.
• Aim for the right planting time so that the beginning of flowering does not involve a lot of dew and constant rain.
• Use fungicides with active ingredients such as methyl thiofanate or phosdifen and kaugamicin