D98 Katoi
Overview
D98 Katoi holds a singular distinction in Malaysia's Department of Agriculture (DOA) durian registry: it is the only variety whose state of origin is listed as "THAILAND." Every other entry in the registry -- all 200-plus of them -- lists a Malaysian state: Perak, Pahang, Penang, Kedah, Selangor, and so on. D98 alone breaks this pattern, its registration candidly acknowledging that this variety came not from any Malaysian orchard but directly from Thailand.
The name "Katoi" is Thai, identifying this as a recognized Thai cultivar that was brought into Malaysia and formally documented by the DOA in 1970. The institutional reporter (Jabatan Pertanian) indicates this was not an accidental discovery by a farmer but a deliberate act of germplasm documentation by the government's agricultural authority.
D98's story does not end with its 1970 registration. Three years later, in 1973, a variety called "Katoi T.9" was registered as D131 from Kedah. This strongly suggests the same Thai cultivar entered the Malaysian system twice under two different codes -- a pattern that echoes, on a smaller scale, the famous triple registration of D158 Kan Yau, which was independently registered as D105 (Perak, 1970), D130 (Kedah, 1973), and D158 (Kedah, 1987). The duplication of Katoi as D98 and D131, like the triplication of Kan Yau, illustrates the decentralized, organic way durian varieties historically moved across the Thai-Malaysian border and entered the registry through different channels without anyone catching the overlap.
Origin & History
D98 was registered on 17 June 1970 by the Department of Agriculture. The state of origin is recorded as "THAILAND" -- not a Malaysian state, but the country itself. This is an extraordinary entry in a registry that was designed to catalog Malaysian durian diversity. Its presence tells us that the DOA, in the course of its documentation work, chose to formally register a Thai variety within the Malaysian system, presumably because the cultivar had been brought to Malaysia for evaluation or was being grown at a government research station.
"Katoi" is a Thai cultivar name. In the broader Thai durian classification system, which recognizes over 234 varieties organized into family groups, Katoi would have been one of many named cultivars circulating in Thailand's durian-growing regions. The exact province of origin within Thailand is not specified in the DOA record.
The 1970 registration date places D98 in the same active documentation period that produced many of the registry's Thai-connected entries. D105, the first registration of Kan Yau from Taiping, Perak, was also registered in 1970. D96 Bangkok A had been registered from Selangor fifteen years earlier, in 1955. D123 Chanee would follow in 1971. This cluster of Thai-origin registrations in the late 1960s and early 1970s reflects a period of active engagement by the DOA with Thai durian germplasm.
The subsequent registration of D131 Katoi T.9 from Kedah in 1973 adds another layer. The "T.9" designation suggests a numbered accession from a Thai collection -- possibly a tree labeled as the ninth specimen in a Thai evaluation series. Kedah, which shares a border with Thailand, is the most natural gateway for Thai durian varieties entering Malaysia overland, and many Thai-origin varieties in the registry (including D130, D158, and D159 Mon Thong) list Kedah as their state of origin. The appearance of Katoi in Kedah just three years after its registration under "THAILAND" suggests the variety was making its way into Malaysian orchards through multiple channels simultaneously.
This pattern -- the same Thai cultivar entering the registry more than once -- is not unique to Katoi. It is perhaps the defining pattern of Thai varieties in the Malaysian system. D158 Kan Yau was registered three times. D123 Chanee appears in the north as D15 under a separate designation. The Bangkok series (D88, D96, D101, D102, D103) may contain overlapping cultivars under different sequential labels. The registry, built over decades through independent reports from different individuals and institutions across different states, had no centralized mechanism to detect these duplications in real time.
Characteristics
The DOA description of D98 is concise, recording only the most essential traits:
Medium-large size (sederhana besar). The fruit falls between medium and large, a size designation shared with many registered varieties and suggesting a commercially respectable fruit.
Thick flesh (isi berisi tebal). The flesh is described as thick, indicating generous aril coverage. Thick-fleshed varieties tend to offer a favorable flesh-to-seed ratio, which is a practical advantage for eating quality. The emphasis on thickness in the DOA description -- "berisi tebal," literally "filled thick" -- suggests this was a notable trait of the fruit.
Yellow flesh (berwarna kuning). The flesh color is yellow, distinguishing it from the orange-yellow of D96 Bangkok A and the deeper orange tones of varieties like D158 Kan Yau. A clear yellow is the most common flesh color among Thai commercial durians, consistent with the major Thai varieties like Chanee and Mon Thong.
Creamy sweet flavor (rasa lemak manis). The "lemak manis" descriptor: rich, buttery, sweet. No bitterness is noted. This places D98 squarely in the sweet, creamy flavor category that characterizes many Thai-lineage varieties in the Malaysian registry. The absence of bitter or complex flavor notes aligns with the general tendency of Thai cultivars toward approachable sweetness.
The DOA record for D98 is notably sparse compared to more thoroughly documented entries. There is no description of the husk color, thorn pattern, fruit shape, stem length, aroma intensity, or texture. This brevity may reflect the variety's foreign origin -- the DOA may have had limited material to work with, perhaps evaluating only a small number of fruits from a single tree.
Availability
D98 Katoi is not available in the contemporary Malaysian durian market. It does not appear in nursery listings, durian stall offerings, or enthusiast forums. No commercial cultivation has been documented.
The variety's dual existence as D98 (Thailand, 1970) and D131 Katoi T.9 (Kedah, 1973) makes its legacy somewhat ambiguous. If any Katoi trees survive in Malaysian orchards, they would more likely be found in Kedah -- the border state where the variety was separately documented -- than in any location traceable to the original "THAILAND" registration. Kedah's northern districts, particularly areas like Sik and Padang Terap where other Thai-origin durians have been cultivated, would be the most natural places to search.
D98's primary significance lies in its unique position in the registry. As the only entry with "THAILAND" as the state of origin, it serves as an explicit acknowledgment of the Thai contribution to Malaysia's durian diversity. While many other varieties in the registry have Thai roots -- D96 Bangkok A, D101, D123 Chanee, D158 Kan Yau, D159 Mon Thong -- they are all listed under Malaysian states, their Thai origins visible only through their names, descriptions, or external research. D98 alone carries Thailand directly in its registry address, a small but telling detail that reflects the honest, unselfconscious record-keeping of the DOA during the decades when it was building the most comprehensive durian varietal database in the world.